RNA biology: Alternative splicing hits synaptic function and behavior

Area of Science:

• Molecular biology
• Neuroscience
• Cell biology

Background:

• The spliceosome is a complex molecular machine essential for RNA splicing.
• Cytoplasmic RNA granules are dynamic structures involved in post-transcriptional gene regulation.
• Neuromuscular junctions (NMJs) are critical for motor control and require precise molecular regulation.

Purpose of the Study:

• To investigate the localization and function of the spliceosome protein SNRNP70 in neuronal cells.
• To explore the role of cytoplasmic SNRNP70 in neuromuscular junction development and function.
• To determine the potential involvement of SNRNP70 in alternative splicing events relevant to NMJ formation.

Main Methods:

• Immunofluorescence microscopy to detect SNRNP70 localization in zebrafish motoneurons.
• Analysis of cytoplasmic RNA granules.
• Functional assays to assess neuromuscular junction integrity and activity.
• RNA sequencing and splicing analysis to identify target mRNAs.

Main Results:

• SNRNP70 was identified in cytoplasmic RNA granules within zebrafish motoneurons.
• Cytoplasmic SNRNP70 was found to be essential for the proper formation and function of neuromuscular junctions.
• Evidence suggests SNRNP70's role in the alternative splicing of z+agrin mRNA, a key NMJ component.

Conclusions:

• The spliceosome protein SNRNP70 has a non-canonical role outside the nucleus, residing in cytoplasmic RNA granules.
• Cytoplasmic SNRNP70 is indispensable for neuromuscular junction functionality.
• Alternative splicing regulation by cytoplasmic SNRNP70, particularly of z+agrin mRNA, is a key mechanism underlying its NMJ-related function.